The only *really* good reason to do it for a FB/P team is if you have a terrible class configuration (like 3 front court players in a class, but even then with FB/P it's much easier to find them all time, so it only really benefits you in that you won't have to replace them all at once later). 12 is always better, if you want to win more games. There are some minor reasons to consider it, like individual player development I guess, but again, with FB/P those guys usually don't have trouble getting pt, so growth isn't normally a big concern. If you're trying to avoid a year with open scholarships, I generally don't think doing that is worth the hit you'll take in games by redshirting a guy. If you're concerned about "wasting" the resources, just don't. pick your worst player, and use the default resources you get to try to find one late session guy to replace him. If you can lock a guy in, cool, cut that loser. If not, nothing lost.